Date: Tue, 10 Dec 1996 03:31:46 GMT
Server: NCSA/1.4.2
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	<title>Digital Images</title>
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<img src=gif/digital.gif> <p>
<h1>
 <a name="top">Digital Images</a><br>
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<p>
A digital image is a two-dimensional array of small square regions known as
pixels.  In the case of a monochrome (also known as gray-scale or
"black-and-white" with shades of
gray) image, the brightness of each pixel is
represented by a numeric value.  
Gray-scale images typically contain values in
the range from 0 to 255, with 0 representing black, 255
representing white and values in between representing shades of gray.  Here is
an example of the above picture blown up to show the underlying pixel values.

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<img src=gif/dig_blow.gif> <p>

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A color image can be represented by a two-dimensional
array of Red, Green and Blue
triples. Typically, each number in the triple also ranges
from 0 to 255, where 0
indicates that none of that primary color is present in that pixel
and 255 indicates a maximum amount of that primary color.


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<address>
  bricker@cs.washington.edu or tanimoto@cs.washington.edu <br>
  Last modified: Tues Mar 8, 23:00:58 PST 1994
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